Power cylinders of internal combustion engines generate intense heat from the combustion cycle. As a result, it is necessary to circulate coolant throughout the engine to reduce operating temperatures. Heat may be especially intense in areas of the engine near the combustion chamber.
Generally, any effort to increase engine cooling by increasing the size of cooling passages comes with a corresponding decrease in engine durability. Engines may be less durable when additional or larger passages are carved out of engine components, e.g., the engine block or cylinder liner areas, in order to achieve greater coolant capacity. Known cooling gallery structures extend generally straight about the perimeter of the power cylinder, e.g., around the perimeter of a cylinder liner and/or engine bore. Adding additional cooling passages or increasing the size of existing cooling passages necessarily results in thinning the walls of the cylinder liner or other engine structures adjacent the combustion chamber. Thinner liner walls, as an example, necessarily reduce the stiffness of the liner, and therefore also reduce the ability of the cylinder liner to resist warping during engine operation.
Accordingly, there is a need in the art for an engine and cylinder liner that offers increased cooling, especially near the engine combustion chamber, while also providing adequate durability.